1. Field of the Invention
The invention relates in general to a capacitance evaluation circuit, and more particularly to a capacitance evaluation circuit for obtaining a capacitance of a to-be-measured capacitor by observing response times of charge and discharge when charge and discharge operations are performed according to a capacitance difference between the to-be-measured capacitor and a capacitance adjustable circuit.
2. Description of the Related Art
Conventionally, a mechanical switch is frequently provided to implement a user control interface device. Because the conventional mechanical switch needs to be in direct contact with the user so as to operate in response to the user's control command, the conventional mechanical device tends to have the structure damage during the user's operation process.
In the modern age, in which the technology changes with each passing day, a touch switch has been available. Conventionally, the touch switch, such as a capacitive switch, performs the control by sensing the variation of the capacitance of the to-be-measured capacitor with the approach of the user or not. However, how to design a capacitance evaluation circuit capable of effectively detecting the variation of the capacitance of the to-be-measured capacitor to enhance the capacitive switch has become an important direction to be developed in the industry.